David Ahrens, director of Brooklyn’s Energy Spectrum, was more helpful: “Microturbines, basically like a small little jet engine, fire from natural gas. They simultaneously produce heat for hot water and electricity, which is interconnected with the Con Ed grid… We anticipate this project will be the equivalent of taking 1,000 cars off the road every year.”

Why? The new energy and heat will mean the apartments’ old boilers (“which burn Number 6 oil,” Mr. Friedman pipes in, not a wonderful thing”) can be intermittently turned off.